Electric contact device working with a liquid, especially mercury



Dec. 1924- 1,517,636

. K. KAISSER ELECTRIC CONTACT DEVICE WORKING WITH A LIQUID, ESPECIALLY MERCURY Filed July 26. 1922 Fig.2.

Patented Dec. 2, 19 24.

, UNITED STATES 1,517,636 PATENT ornca.

KARL KAISSER, or MUNICH, GERMANY, ASSIGNOR T0 METALLBANK UND METAL- LURGISCHE GESELLSGHAFT, AKTIENGESELLSCHAFT, 0F FRANKFORT-0N-THE- MAIN, GERMANY, A CORPORATION or GERMANY.

ELECTRIC CONTACT DEVICE WORKING WITH ALIQUID, ESPECIALLY MERCURY.

Application filed July 26, 1922. Serial No. 577,566.

With mercury interrupters 1t is known to break the circuit by removing an insulating cup containing mercury, from a receptacle containing mercury in such a way that the entire rim of the cup issues at once. In order to make the entire rim of the cup effective for said interruption, either the cup had to be lifted out of the mercury or the mercury receptacle had to be lowered in relation to the cup, with the rim of the cup in a perfectly horizontal position in either case.

The present invention relates to an electric contact device working with a liquid, especially with mercury, the contact body of which is provided with an insulated receptacle for the contact liquid. In contrast to the arrangement used with mercury interrupters, the important point in the resent invention is that the receptacle on tlie contact body is placed transversely to the direction of movement of the contact liquid in such a manner that the liquid flowing past and thereby rising above the rim of said receptacle, can flow thereinto from all sides in any position of the passage for the liquid, and thus complete the circuit. Whilst, with mercury interrupters, the entire rim of the cup must always cooperate in breaking the circuit, and consequently the axis of the cup must always be in a vertical position, the contact device according to the present invention can also work with the rim of the contact cup in an inclined position because the contact liquid flows into and out of the receptacle transversely.

For this purpose the contact member, or members, as the case may be, is arranged to project into a channel containing the conducting liquid such as mercury, which is arranged -to be tiltable about an axis of support to open and close the interrupter. Within this channel, and surrounding the contact member, is an insulating barrier forming a collecting receptacle about the member. Through the walls of this barrier, on opposite sides of the contact member, are twopassageways positioned transversely of the plane of tilting of the channel, and. therefore, transversely of the direction of movement of the conducting liquid with re spect to the channel as the interrupter is moved from open to closed position, or vice versa. As the device is moved to one or the other of these positions the conducting liquid, upon reaching the level of these opposed passageways, is compelled to flow therethrough into or out of the collecting receptacle substantially transversely to the plane of tilting. Hence, there is no contact between the mercury and the contact member until this point is reached, but, once it is reached, the mercury flows into or out of the collecting receptacle from opposite sides and positively establishes electrical contact over a conductive area of substantial size and eliminates any tendency to the formation of an arc.

For the purpose of facilitating the inflow of the contact liquid to the interior of the receptacle, it is advisable to chamfer the upper rim of the receptacle, or give it an outward taper.

The insulated collecting receptacle is arranged in such a manner, that the entire cross-section of the liquid passage is to be filled up with the exception of the requisite intake and outlet ducts or channels. Apart from the firm mounting ensured by building the collecting receptacle into the liquid passage in this manner, an essential economy in contact liquid is secured, because the contact body forms a core piece and leaves only so much space for the contact liquid in the liquid passage, as is required by the conductive cross section of the contact device.

With tiltable contact devices, the core piece formed by the collecting receptacle is preferably provided with an inlet duct of small diameter, and one or more exit channels of a larger diameter which communicate with the chamber of the recep tacle. In this way a slow inflow and a quick outflow of the contact liquid are effected as is shown for instance in the specification of my U. S. patent application Serial No. 427, 121 filed Nov. 29, 1920.

The invention further enables a compensating space with preferably controllable admission to be inserted between the inlet duct and outlet channels of the core piece. In this compensating space the inflowing liquid can collect and come to rest, before reaching the contact body. This compensating action of the inserted chamber becomes advantageously apparent, especially in the case of switching the tilting receptacle in and out in quick succession.

By further arranging the connecting opening between the receptacle spaces and the outlet channel transversely in relation to the movement of the liquid, and by arranging the bottom of the outlet channel at a corresponding level below the inlet openings to the collecting receptacles or catch pots, it becomes almost certain, in the'event of the device being rapidly tilted back into the on position that any remaining liquid which may be present will be prevented'from flowing back from the outlet channel into a collecting receptacle or catch pot, or from touching a contact, which in ordinary working should not be reached until after preceding contact steps have been switched in. The invention ensures, in such cases, that the remaining liquid will flow past the later catch pots, and will first reach the first contact stage.

In order to understand the invention more clearly reference is made to the acompanying drawings which show by way of example, several embodiments of the invention.

Fig. 1 shows the state of affairs at the beginning of completing the circuit in a mercury switch without a mercury cup.

Fig. 2 is a longitudinal section through one embodiment of the device.

Fig. 3 is a longitudinal section through another embodiment of the device.

Fig. 4 is a longitudinal section through a tiltable switch with several contact bodies.

, Fig. 5 1s a cross section along the lines I -II' of Fig. 4.

If, for the purpose of contact closing in the way shown in Fig. 1 the mercury 1 is fed sideways to the contact body 2, first of all, the rounded edge 3, due to the sluggishness of the mercury, touches the contact 2, that is, the contact is only closed over an insufiicient conductive area, and in consequence of the heat generated a gap will be produced between 2 and 3, which results in the formation of an arc, until the oncoming mass of mercury provides the required conductive area. Owing to the formation of sparks the contact surface 2 is naturally damaged, this being burnt and made unsuitable for proper working.

'If, however, according to Fig. 2 the contact 4 is surrounded by a receptacle or catch pot of insulating material (known per se), or 1f it is located therein, the mercury 6 which flows in transversely to the receptacle or catch pot 5 rises above the rim thereof, thereupon running into said receptacle, mixing with the mercury still retained in said receptacle from a previous contact operation, and thus establishes connection with the contact 4. In this way contact is effected at once over the whole sectional area of the receptacle or catch pot 5, or the contact 4. Even if the receptacle 5 is empty, that is if no mercury has been left therein from a previous contact operation, the sudden inflow of mercury covers the whole contact surface of the contact 4 immediately, provided the diameter and the depth of the receptacle or catch pot 5 are of suitable dimensions. It is essential that the receptacle 5 be arranged transversely in relation to the direction of movement of the mercury, because of the resulting assurance of reliable working, even in an inclined position of the mercury passage and of the rim of the receptacle or catch pot, since the mercury can pour in from any side.

In the embodiment shown in Fig. 3 the collecting receptacle or catch pot 5 is arranged in a suspended contact 7. The action is, however, the same as in a standing contact according to Fig. 2. A special advantage of the modification shown in Fig. 3 is that no resistance is offered to the mercury flowing off transversely in relation to the axis of the rec eptacle or catch pot 5 when the apparatus is being switched off, as may be the case to some extent in the modification shown in Fig. 2.

The arrangement may be such that, as shown in the drawings, the receptacle or catch pot 5 remains entirely filled at every break of the mercury contact. Of course. there is nothing to prevent it from remaining only partially filled, or from being completely emptied, because the sudden closing of thecontact intended to be effected accord ing to the invention, can of course also be be attained when the receptacle or catch pot 5 is empty, as can be easily seen from the description, and from Figs. 2 and 3. For the purpose of facilitating the sudden influx of the mercury into the interior of the receptacle-or catch pot, the rim thereof may be bevelled in the way shown in Figs. 2 and 3, or tapered outwardly.

he example according to Figs. 4 and 5 shows a tiltable contact device of the kind shown in the specification of my patent ap-- plication Serial No. 427,121 with the widened vessel 9. tiltable around the axis 8, for the contact liquid connected to the tubular passage 10 with the contacts 11 to 16. The passage 10 is filled up by an insulating core piece 17, which at the positions occupied by the contacts 18 of the terminals -11-16 forms the collecting receptacles or catch pots 19. The core piece 17 leaves only a small duct 20 in the passage 10 free for the admission. and two lateral channels 21 for the removal. of the contact liquid. Connect-ion between the channels 21 and the chamtion of movement of the liquid flowing in the channels 21.

The core piece 17" is retained in the passage 10 by any suitable means, for example. a screw 23. On the end further away from the vessel 9 the passage 10 which is closed by means of a cover 24 forms a chamber 25 which is connected with the outlet channels 21. The sectional area of the opening of the connection 26 between 25 and 20 is regulated by a set screw 27 which may advantageously be sealed. That end of the core piece 17 which faces the collecting vessel 9 extends into a screw piece 28. into the tube 2) of which open the lateral channels 21 for the removal of the liquid. whilst the conduit 30 of same establishes communication between the vessel 9 for the liquid and the inlet duct 20.

As is shown in Fig. 4 when the contact device is being tilted into the switching-on position. that is in the direction of the arrow shown in Fig. 4. the contact liquid passes from the vessel 9 through the conduit 30 and duct 20 and the correspondingly adjusted openings 26. first into the compensating space 25. whence it reaches the lateral channels 21. In rising in the channels 21 the liquid runs through the openings 22 into the catch pots 19 of the contact stages 1611. and thereby effects a quick closing of the contacts. As shown especially in Fig. 5. the construction of the catch pots 19 with a core piece 17 filling upv the passage for the liquid effects a substantial economy in contact liquid. because only sectional areas 20 and 21 of dimensions absolutely essential for the inlet and outlet of the liquid. need be left free.

The chamber 25. in combination with the transverse arrangement of the inlet openings 22 and the low-level position of the lateral channels 21. prevents the inflowing liquid from splashing on to the later contacts without operating the first contact stages. Moreover. it is impossible that. when quickly tilting the switch from the off intothe on position. any residual liquid can make its way from the channels 21 to the contact stages l1-15 because the relative position of the inlet openings 22 and the low-level position of the channels 21 ensures that such liquid below the openings 22 must first flow into the compensating chamber 25. or into the collecting receptacle or catch pot of the first contact stage 16. i

What I claim is: 1. In a tiltable electric contact device working with a liquid electrical conductor, especially mercury, in combination, a channel for the liquid conductor. a contact member projecting into said channel. an insulating barrier within the channel and surounding said contact member to form acollecting receptacle about the member. said barrier having opposed passageways t-herethrough positioned transversely of the plane of tilting of said channel sothatas such tilting takes place the conducting liquid upon reaching the level of said passageways is -compelled to flow into the collecting receptacle substantially transversely to the plane of tilting and positively close the circuit.

2. In an electric contact device working with a liquid electrical conductor. especially with mercury. in combination. a channel for the liquid conductor. a contact member projecting into said channel transversely to the direction of movement of the liquid conductor. and an insulated receptacle on or beside the inner projecting end of said contact member. said insulated receptacle occupying thesectional area of the channel for the liquid conductor with the exception of that portion required for the intake and outlet ducts. all in such a way that the liquid electrical conductor flowing past and thereby rising above the rim of said receptacle can flow laterally into the interior thereof if said channel. the contact member and its receptacle are in an inclined position.

In an electric contact device working with a liquid electrical conductor. especiallv with mercury. in combination. a channel for the liquid conductor. a contact member projecting into said channel transversely to the direction of movement of the liquid conductor and an insulated core piece occupying the sectional area. of said channel with the exception of that portion required for the intake and outlet'ducts and forming a receptacle beside said contact member, the inlet duct being of small cross-section and the outlet duct of larger cross-section and both ducts being in communication with said receptacle.

4. In an electric contact device working with a liquid electrical conductor. especially with mercury. in combination. a channel for the liquid conductor. a contact member projecting into said channel transversely to the direction of movement of the liqiud conductor and an insulated core piece occupying the sectional area of said channel with the exception of that portion required for the intake and outlet ducts and forming a receptacle beside said contact member. the inlet duct being of small cross-section and the outlet duct of larger cross-section and both ducts being in communication with said receptacle and a compensating chamber arranged between the intake and outlet ducts of said core piece.

5. In an electric contact device working with a liquid electrical conductor, especially with mercury, in combination, a channel for the liquid conductor, a contact mem ber projecting into said channel transversely to the direction of movement of the liquid conductor and an insulated core piece ccupying the sectional area of said channel with the exception of that portion required for the intake and outlet ducts and forming a collecting receptacle beside said contact member, the inlet duct being of small crosssection and the outlet duct of larger crosssection and both ducts being in communication with said receptacle, a compensating chamber arranged between the intake and and outlet ducts of said core piece and an opening arranged between the collecting receptacle of the core piece and the outlet duct, transversely to the direction of movement of the liquid conductor.

6. In an electric contact device working with a liquid electrical conductor, especially with mercury, in combination, a channel for the liquid conductor, a plurality of contact members projecting into said channel transversely to the direction of movement of the liquid conductor and an insulated core piece occupying the sectional area of said channel with the exception of that portion required for the intake and outlet ducts and forming collecting receptacles beside said contact members, the inlet duct being of small cross-section and the oulet duct of larger cross-section and both ducts being in communication with said receptacles, a compensating chamber'arranged between the intake and outlet ducts of said into said compensating chamber or into the collecting receptacle formed by the core piece of the first contact stage and pass into the receptacles of the later contacts.

In testimony whereof I aflix my signature in presence of two witnesses.

KARL KAISSER. Witnesses:

A. CLAUDE HoUcH'roN, ALEXANDER DE SOTO. 

